Malicious PDF — malware analysis report

Static analysis result for SHA-256 f5d225843be40690…

MALICIOUS

PDF

76.6 KB Created: 2021-06-12 21:10:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: b11fe4bc0cf461446b1641527ef7c49c SHA-1: 307e0eb3e4b96ff35c51417ed33d198df5a333b8 SHA-256: f5d225843be40690d354b419eaf0a84a1842864331cf59e3057a17af20213c3b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file is identified as malicious by ML classifiers and ClamAV, indicating it is a phishing or trojan PDF. It contains numerous embedded URLs pointing to compromised WordPress sites and other disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of external URI heuristics and link farm detections strongly supports a phishing or malware distribution attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://chcial.ru/uplcv?utm_term=deviant+behavior+in+sports PDF link annotation
    • https://action-roofing.com/wp-content/plugins/super-forms/uploads/php/files/87f8fe4e72df828212295548ec0e7c19/fafarekusefidamaj.pdfIn PDF document text
    • http://www.monts.sk/upload_images/file/pitodikol.pdfIn PDF document text
    • http://klimagra.pl/images/wysiwyg_img/file/13268539100.pdfIn PDF document text
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/160b28f1d6d676---gunuro.pdfIn PDF document text
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606e3833c3057---56482233171.pdfIn PDF document text
    • https://iescolumbus.org/wp-content/plugins/super-forms/uploads/php/files/a24628caf3aae8100b75e595a734cf0a/tulusabevekemutelapup.pdfIn PDF document text
    • http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/160775091ee58f---xapefabupewonofeb.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b54567b6cee---8282625621.pdfIn PDF document text
    • http://objetivovender.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cfa2c63e73---7326922484.pdfIn PDF document text
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/1607dfb1c7d64b---bexobusowirokufujen.pdfIn PDF document text
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16081fcac9ed3c---16896934493.pdfIn PDF document text
    • http://www.hj-bouwt.be/wp-content/plugins/formcraft/file-upload/server/content/files/160b76955961e7---30314754594.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bcb0e340bb9---kizifonasefuvijonikivuje.pdfIn PDF document text
    • http://abc-tel.ru/data/File/kilofanifoz.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ef38.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF38 5072 bytes
SHA-256: 6dd9d8bdbd473a286dcd5b0b6d679397a1846a0ac032f2bd876b503df1d5d36d
font_01_sfnt_off00010077.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10077 10956 bytes
SHA-256: 7d1bc905b1aad9e8501cad48e96acc8f409adc85e9ec35937d9da514fa894abe